diff --git a/lambda/alert.c b/lambda/alert.c
index 258487f..acd8a37 100644
--- a/lambda/alert.c
+++ b/lambda/alert.c
@@ -17,8 +17,8 @@
 #include "pins.h"
 
 volatile uint8_t beepCount = 0;
-volatile uint16_t beepLength = 0;
-volatile uint8_t oscCount = 0;
+volatile uint8_t beepLength = 0;
+volatile uint16_t oscCount = 0;
 
 volatile static bool alertActive = false;
 volatile static bool keepActive = false;
@@ -46,10 +46,10 @@
 void beep(uint8_t const beeps, uint8_t const length, uint16_t const tone) {
 	OCR1A = tone;
 	if (TCNT1 >= tone) TCNT1 = 0;
-	oscCount = 0;
-	beepCount = beeps;
 	ATOMIC_BLOCK(ATOMIC_FORCEON) {
 		beepLength = length;
+		oscCount = 0;
+		beepCount = beeps;
 	}
 }
 
@@ -58,12 +58,12 @@
 		bool const keep) {
 	OCR1A = tone;
 	if (TCNT1 >= tone) TCNT1 = 0;
-	alertActive = true;
-	keepActive = keep;
-	oscCount = 0;
-	beepCount = beeps;
 	ATOMIC_BLOCK(ATOMIC_FORCEON) {
+		alertActive = true;
+		keepActive = keep;
 		beepLength = length;
+		oscCount = 0;
+		beepCount = beeps;
 	}
 	displayText(line0, line1);
 }
diff --git a/lambda/command.c b/lambda/command.c
index b7d6fdc..3b17dc4 100644
--- a/lambda/command.c
+++ b/lambda/command.c
@@ -98,7 +98,7 @@
 		if (fields[2] != '\0') {
 			tone = atoi(fields[2]);
 		}
-		beep(1, length, tone);
+		beep(3, length, tone);
 	}
 	else if (strcmp_P(fields[0], PSTR("sa")) == 0) {
 		// set airgate
diff --git a/lambda/rules.c b/lambda/rules.c
index b39c2f3..64fd057 100644
--- a/lambda/rules.c
+++ b/lambda/rules.c
@@ -90,7 +90,8 @@
 static void airgate25(bool* const fired, Measurement const meas) {
 	if (state == burning_down && ! isAirgateBusy() &&
 			meas.tempI < TEMP_AIRGATE_25 &&
-			meas.lambda >= LAMBDA_TOO_LEAN && getAirgate() > AIRGATE_25) {
+			meas.lambda >= LAMBDA_TOO_LEAN &&
+			getAirgate() > AIRGATE_25) {
 		setAirgate(AIRGATE_25);
 		alert_P(BEEPS, LENGTH, TONE, PSTR(MSG_AIRGATE_25_0), PSTR(""), false);
 		*fired = true;
@@ -104,7 +105,8 @@
 static void airgateClose(bool* const fired, Measurement const meas) {
 	if (state == burning_down && ! isAirgateBusy() &&
 			meas.tempI < TEMP_AIRGATE_0 &&
-			meas.lambda >= LAMBDA_MAX && getAirgate() > AIRGATE_CLOSE) {
+			meas.lambda >= LAMBDA_MAX &&
+			getAirgate() > AIRGATE_CLOSE) {
 		setHeaterState(heaterStateOff);
 		closeAirgateAndSleep();
 		alert_P(BEEPS, LENGTH, TONE,
@@ -123,8 +125,10 @@
  */
 static void tooRich(bool* const fired, Measurement const meas) {
 	if (! isAirgateBusy() &&
-			meas.tempI > TEMP_FIRE_OUT && meas.lambda < LAMBDA_TOO_RICH &&
-			getHeaterState() == heaterStateReady && getAirgate() < AIRGATE_50) {
+			meas.tempI > TEMP_FIRE_OUT &&
+			meas.lambda < LAMBDA_TOO_RICH &&
+			getAirgate() < AIRGATE_50 &&
+			getHeaterState() == heaterStateReady) {
 		setAirgate(AIRGATE_50);
 		alert_P(BEEPS, LENGTH, TONE, PSTR(MSG_AIRGATE_50_0), PSTR(""), false);
 		*fired = true;
@@ -137,8 +141,10 @@
  */
 static void tooLean(bool* const fired, Measurement const meas) {
 	if (! isAirgateBusy() &&
-			meas.tempI > TEMP_AIRGATE_50 &&	meas.lambda > LAMBDA_TOO_LEAN &&
-			getHeaterState() == heaterStateReady && getAirgate() > AIRGATE_50) {
+			meas.tempI > TEMP_AIRGATE_50 &&
+			meas.lambda > LAMBDA_TOO_LEAN &&
+			getAirgate() > AIRGATE_50 &&
+			getHeaterState() == heaterStateReady) {
 		setAirgate(AIRGATE_50);
 		alert_P(BEEPS, LENGTH, TONE, PSTR(MSG_AIRGATE_50_0), PSTR(""), false);
 		*fired = true;
@@ -167,7 +173,8 @@
  */
 static void warmStart(bool* const fired, Measurement const meas) {
 	if (! *fired && state == firing_up &&
-			meas.tempI > TEMP_FIRE_OUT && tempIMax >= TEMP_AIRGATE_50) {
+			meas.tempI > TEMP_FIRE_OUT &&
+			tempIMax >= TEMP_AIRGATE_50) {
 		setSleepMode(false);
 		resetRules(false);
 		tempIMax = meas.tempI;
@@ -224,7 +231,7 @@
 			getHeaterState() == heaterStateFault) {
 		return;
 	}
-	if (getHeaterUptime() >= 1800 && meas.tempI < TEMP_FIRE_OUT &&
+	if (getHeaterUptime() >= 1800 && meas.tempI < TEMP_HEATER_TIMEOUT &&
 			meas.lambda >= LAMBDA_MAX) {
 		setHeaterState(heaterStateOff);
 		closeAirgateAndSleep();
diff --git a/lambda/rules.h b/lambda/rules.h
index f2f103f..e4e764f 100644
--- a/lambda/rules.h
+++ b/lambda/rules.h
@@ -40,9 +40,11 @@
  */
 #define TEMP_AIRGATE_0 450
 /** Temperature at which to consider the fire to have gone out */
-#define TEMP_FIRE_OUT 90
+#define TEMP_FIRE_OUT 70
 /** Min. temperature at which to consider the fire to fire up again */
-#define TEMP_FIRE_OUT_RESET 100
+#define TEMP_FIRE_OUT_RESET 80
+/** If the temp. is below this value, switch off the heater after a timeout */
+#define TEMP_HEATER_TIMEOUT 100
 /** Max. lambda value that can be measured */
 #define LAMBDA_MAX 2000
 /** Combustion is considered too rich if lambda is below this value */